Portion of a countertop



FIG. 1 is a perspective view of a portion of a countertop embodying the invention; and,

FIG. 2 is a left side view of the portion of the countertop of FIG. 1.

The broken line showing of the environment is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a portion of a countertop, as shown and described. 